Wrench sockets have been utilized for applying torque to nuts and the heads of bolts of threaded fasteners. Often, ratchet-type wrench drivers are utilized as drive members for coupling to the wrench sockets to provide driving torque. Prior art wrench sockets have included both wrench sockets of fixed size and wrench sockets having size-adjustable jaws, which may be adjusted for accommodating fastener heads of various sizes. As used herein, the term fastener head includes either a nut or a bolt head, such as that having an hexagonally shaped profile which defines drive surfaces that may be engaged by a wrench socket for transferring torque from the wrench socket to the threaded fastener. Size adjustable wrench sockets have been used both with wrench drivers which have handles that extend at angles such as ninety degrees to an axis of rotation of the wrench sockets, and with in-line drivers in which the handles extend in-line with the axis of rotation of the wrench sockets, such as nut drivers and the like.
Prior art size adjustable wrench sockets have included size adjustable jaws which are mounted to jaw guide members having guide surfaces upon which portions of the jaws slidably engage. These prior art wrench sockets have also included upwardly extending members which engage within slotted collars which are rotatably mounted above the jaw guide members for rotating to move the jaws radially inward and radially outward until the spacing between the jaws is such that torque may be transferred from the wrench sockets to the threaded fasteners. Bias springs have been utilized to bias the jaws to into radially outward positions relative to the jaw guides. Some prior art size adjustable wrench sockets have been continuously adjustable, over continuous ranges of sizes. Other size adjustable wrench sockets have been provided with indexed settings, which correspond to standard sizes of threaded fastener. However, prior art size adjustable wrench sockets have typically proven unsatisfactory in that they fail to provide wrench sockets of adequate strength for remaining engaged with fastener heads when large amounts of torque are applied to the wrench sockets and the fastener heads.